Locking wheel bolts and nuts: common defects and their signs

1. Deformation
   • Free play when rocking the wheel.
   • Body vibration near a certain wheel is felt during driving.
2. Corrosion
   • Problems with unscrewing the fasteners.
   • Wheel free play and foreign sounds appear during driving.
   • Rustling sound is heard when unscrewing the fasteners.
3. Wear-out or striping of thread
   • The wheel is fixed loosely.
   • In some cases the wheel can get detached during driving.
   • It is impossible to unscrew a fastener.

How to repair and replace locking wheel bolts and nuts?

If the corrosion process is on the early stage and its spots are not significant, you can clean wheel bolts or nuts with a metal brush or by sandblasting, and then apply special anti-corrosion grease to the component. It is strongly not recommended to repair worn-out parts, recut the thread, for example, because such fasteners won’t provide a reliable wheel attachment and their use can cause a road accident.

If wear-out or damages are significant, wheel nuts or bolts are to be immediately replaced. Every car owner can do this themselves. The replacement algorithm includes the following actions:

1. Set the car onto an even surface, loosen wheel bolts and nuts.
2. Lift the car body with a jack.
3. Unscrew fasteners.
4. Demount the wheel and inspect fastener seats for corrosion. Clean the surface if necessary.
5. Set the wheel into its place, install wheel fasteners having applied anti-corrosion compound to them and then screw them in loosely. Remember, that it is prohibited to use oil and graphite greases because they promote random unscrewing of fasteners in the following.
6. Lower the car to the ground, tighten fasteners.

It is recommended to use a torque wrench for tightening bolts or nuts on a car in order to avoid under- or overtightening. Moreover, it is recommended to screw them in a certain order, otherwise there’s a risk to install the wheel in a wrong position. This sequence will differ for cars of different models according to quantity of bolts or nuts. Information concerning tightening order and the necessary torque is specified in a vehicle manual.

Usually, only the broken down component is subject to replacement.
Follow tightening torque, recommended by the car manufacturer. Use a torque wrench for it.
Use a special greasing compound for wheel nuts during installation.

Types:

1. By configuration of the holding-down part of the fasteners:
   • with the flat surface;
   • with the conical surface;
   • with the spherical surface.
2. By nut outlet type:
   • open;
   • close.
3. By material:
   • steel;
   • titanium;
   • aluminium.
4. By protective coating type:
   • without coating;
   • with zinc coating;
   • with chrome coating;
   • with nickel coating.